A clinicopathological study of sinonasal neuroendocrine carcinoma and sinonasal undifferentiated carcinoma

Objective: Sinonasal undifferentiated carcinoma (SNUC) and sinonasal neuroendocrine carcinoma (SNEC) are relatively newly recognized, rare entities requiring further clinicopathological analysis to advance our understanding and determine prognostic distinctions between them. Study Design: Retrospective chart review. Methods: Cases were retrieved from the Copath system. One patient was seen in consultation from an outside institution. Histological and immunohistochemical findings, patient demographics, treatment regimens, and outcomes were analyzed and compared. Results: Ten patients (7 men, 3 women) ranging in age from 17 to 58 years (mean age, 44.7 y) were included. Four patients were classified with SNEC, six as having SNUC. The predominant site was the superior nasal cavity or ethmoids (seven cases), followed by the maxilla (four cases). Disease in four patients was clinically staged as N1 (three with SNUC, one with SNEC), and in six patients as NO (three with SNEC, three with SNUG). Of the nine patients who were treated initially with surgical resection, seven received postoperative radiation therapy alone, one received postoperative radiation and chemotherapy, and one had only limited postoperative chemotherapy. One patient was treated with radiation therapy and chemotherapy alone, without surgical resection. Follow-up was obtained ranging from 6 to 108 months (mean period, 26.4 mo). Three patients died of disease 10, 14, and 41 months, respectively, after diagnosis. Three patients had persistent disease at 6, 9, and 21 months, respectively, two of them with distant metastases. Four patients were disease free after 6, 18, 31, and 108 months, respectively. Conclusions: SNUG and SNEC are both aggressive tumors, usually presenting in middle age as a nasal mass. Both tumors have the capacity to metastasize locally and distantly, and both can result in poor outcomes. This small series precludes a demographic or prognostic distinction between the two groups.